P code generator of GPS system, generation system and method

Abstract

The invention provides a P code generator of a GPS system, a generation system and a method. The generator includes a feedback displacement register module, an X1 sequence generating module, an X2 sequence generating module, a delay module and a P code generation module. Each feedback displacement register, based on the parameters configured in an upper computer, generates m sequences. A counter in the feedback displacement register truncates the m sequences to obtain 4 different sequences, further xors or truncates the 4 sequences to obtain a X1 sequence and a X2 sequence. The X2 sequence undergoes a delay unit, and then together with X1 sequence are xored and truncated to obtain a P code. According to the invention, the P code generator can be operated in a FPGA-based hardware platform, can generate the P code in hardware structures, and stores the P code in an internal memory. Also, the P code generator takes less storage resources.

Description

technical field [0001] The invention relates to the technical field of satellite navigation, in particular to a P code generator, a generating system and a method of a GPS system. Background technique [0002] With the expansion of the exploration scope of human activities and the improvement of the level of science and technology, the satellite navigation system has become an important infrastructure of the information system and a key technical support system directly related to the national economy and people's livelihood. At present, the most widely used is the GPS receiver, which can accurately Measure the P code phase for precise positioning. The P code, also known as the precise ranging code, can be modulated on the L1 and L2 carrier signals at the same time. It is mainly used in environments with high requirements for precise ranging, anti-interference and confidentiality. However, due to the long period and complex structure of the P code, in the research on the P c...

AI Technical Summary

Problems solved by technology

However, due to the long period and complex structure of the P code, in the research on the P code of the GPS system navigation simulator, if the P code is stored in the on-chip memory and extracted by a lookup table, it will take up too many programmable devices If the storage resources are stored in the off-chip memory or sent by the upper mathematical simulator, the real-time performance of the P code phase cannot be guaranteed, and the whole system will become more complicated. Realize the generation of P code on the system

[0003] In view of the long period and complex structure of the P code, it is difficult to realize the generation of the P code on the hardware system with limited resources during the research on the P code of the GPS system navigation simulator, and no effective solution has been proposed yet

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